03/04/2019
What’s new in TypeScript 3.4
The production version of TypeScript 3.4, the latest version of Microsoft’s typed superset of JavaScript, has arrived, with improvements for builds and type-checking.
The new features in TypeScript 3.4
-- A new compilation flag, --incremental, provides faster subsequent builds.
--Type-checking is introduced for the ECMAScript globalThis global variable, providing a standard way for accessing the global scope that can be used across different environments.
--It is now easier to read-only array types, with a new syntax for ReadonlyArray using a Readonly modifier for array types.
--Support is introduced for read-only tuples; any tuple type can be prefixed with the readonly keyword to make it a read-only tuple.
--The readonly modifier in a mapped type automatically will convert array-like types to a corresponding read-only array type.
--A new construct has been introduced for literal values, const assertions.
--As a breaking change, the type of top-level this is now typed as typeof globalThis instead of any.
--Another breaking change is that improved inference in TypeScript 3.4 might produce generic functions rather than functions that take and return constants.
https://lnkd.in/dZ5MD2x
